Northstar Engines and System Technical Discussion Discussion, Rough running 2000 Seville in Cadillac Engine Discussion; My 2000 Seville with 70,000 miles is idling and accelerating rough. I took it to the Cadillac Dealer and the ...

Rough running 2000 Seville

My 2000 Seville with 70,000 miles is idling and accelerating rough. I took it to the Cadillac Dealer and the Dealer said that the no. 3 clyinder is pumping oil and they need to remove the engine for further investigation. Is there a bulletin covering this problem?

Re: Rough running 2000 Seville

I seriously doubt that this is your problem. There is a service ring and piston kit that is used for serious oil consumption cases....but....it sounds like the dealer is applying it to all possible cases for the warranty $$$...

The only way this could cause your problem is if the plug was seriously fouled for number 3. Oil consumption will not cause the engine to run rough. If a plug fouls it will missfire and run rough...but...replacing or cleaning the plug should cure the problem..at least temporarily.

Search thru the archives using the search feature in the forum tool bar above. Type "oil consumption" in and read my posts. Lot of info on this.

Are you having to add a lot of oil to the engine?? If the engine is truely "pumping oil" bad enough to cause a problem like that you should be having to add a quart every 500 miles or so. Even at 1 quart per 1000 miles the engine could be fine and require absolutely no work.

Try some wide open throttle accels to clean the carbon out of the combustion chambers and exercise the rings. The engine needs some heavy throttle, high RPM operation to keep it exercised. Flog it hard and often. This is covered in posts in the archives.

If it is an original, unmolested 2000 with those miles the first thing that I would consider for rough running, stalling, etc... is replacing the crank sensors. There are frequently problems with the 2000 model generation crank sensors that can cause problems and not set any diagnostic codes..including no starts on occasion. I would suspect that before any oil consumption issue causing a driveability problem.